THE man arrested for a mass stabbing at a Japanese facility for the disabled reportedly told police: “It would be better if disabled people disappeared.”

At least 19 people were killed and up to 26 others wounded in a stabbing frenzy that local media has deemed Japan’s worst mass murder since World War II.

The suspect, identified as Satoshi Uematsu by officials in the Kanagawa prefecture, was previously “hospitalised” in February this year after he attempted to present a letter to a politician in which he called for the “euthanasia” of disabled people, according to local broadcaster NTV. He wrote in the letter that the government should allow for euthanasia of disabled people and that he would be willing to carry out the acts himself.

Police said they responded to a call about 2:30am from an employee saying something horrible was happening at the facility in the city of Sagamihara, 50km west of Tokyo.

About two hours later a man turned himself in at a police station, police in Sagamihara said.

Uematsu had worked at the facility until February. Japanese media reports said he was 26 years old.

Uematsu allegedly entered the building about 2:10am by breaking a glass window on the first floor of a residential building at the facility, a health official told reporters at a news conference.

Japanese broadcaster NTV reported that Uematsu was upset because he had been fired, but that could not be independently confirmed.

The facility, called the Tsukui Yamayuri-en, was home to about 150 adult residents who have mental disabilities, Japan’s Kyodo News service said.

The "Keep Out" tape by police is displayed at the Tsukui Yamayuri En, after a mass stabbing took place.Source:AFP

Uematsu told police he used to work at the centre and also told them, “It would be better if disabled people disappeared,” The Japan Times reported.

The Tsukui Yamayuri-en facility provides overnight and daycare services for people with a wide range of disabilities, and has a swimming pool, gym and medical clinic.

The facility is situated in three hectares (7.6 acres) of grounds. It was established by the local government and nestled on the wooded bank of the Samagi River.

The Sagamihara City fire department said 19 people were confirmed dead in the attack and authorities have warned the death toll could rise again.

The facility seen on Google Street View.Source:Supplied

Television footage showed a number of ambulances parked outside the facility, with medics and other rescue workers running in and out.

Police in Sagamihara, Kanagawa Prefecture, arrested a suspect after he went to a police station half-an-hour later and told them: “I did it,” Kyodo news agency reported.

He left the knife in his car when he entered the station. He has been arrested on suspicion of attempted murder and trespassing.

Ambulance crew and firefighters work outside a facility for the handicapped where a number of people were killed and dozens injured.Source:AP

A man identified as the father of a patient in the facility told Japan’s broadcaster NHK he learned about the attack on the radio and had received no information from the centre.

“I’m very worried but they won’t let me in,” he said, standing just outside a cordon of yellow crime-scene tape.

A neighbour told media a man with blond hair and wearing black clothes was being held by police.

The stabbing attack is one of the country’s worst post-war mass murders, with the death toll exceeding similar horrific cases before it.

Mass killings are relatively rare in Japan, which has extremely strict gun-control laws.

In 2008, a man named Tomohiro Kato killed three people when he drove a truck into a crowd; he then went on a stabbing spree and attacked at least 12 others using a dagger, killing four and injuring eight.

In 2001, eight children were stabbed to death at their Osaka school by a former janitor.

In 1995, a cult group released sarin on several Tokyo subway lines, killing 12 people, severely injuring 50 and causing vision problems for close to 5,000 others.

Japan has the lowest crime rate in the world, but despite this, the country has recently seen an increasing number of cases of attacks on the weak and vulnerable.

In February, a former nursing home worker was arrested for allegedly throwing an 87-year-old resident from a balcony to his death.

The former employee also reportedly admitted killing two more residents in their 80s and 90s by throwing them from balconies in 2014.

There have also been cases of family members killing ailing and ageing spouses or parents suffering from dementia in Japan’s rapidly ageing society.